We took the ferry from Venice to Patras ten years ago.

Small car, 4 people, outside cabin with window:

It isn't very cheap, this year the above will cost in July: GB £ 1,239.40 return
but considering you have 2 nights on the ship and save a very long drive it is quite attractive to me.

You need to book soon, as May bookings are filling up!!

http://www.aferry.co.uk/timetable/Ve...oanLinesuk.htm

http://www.minoan-lines.ch/